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L-theanine supplements, compared

13 products we’ve reviewed list l-theanine as a key ingredient. Here’s what it does, what the research uses — and how much each product actually contains.

What it is

An amino acid found in tea, often paired with caffeine to smooth out the jittery edge or used on its own for relaxation. Research is early: a small 2019 randomized trial (30 adults, 200 mg a day for four weeks) found improvements in self-reported stress and sleep measures.

What the research uses

Clinical studies commonly use 100–400 mg a day; 200 mg is typical.

Educational information, not medical advice. Talk to a healthcare professional before starting a supplement, especially if you are pregnant, nursing or take medication.

Every product, dose by dose

ProductL-theanine per servingFormScore
BULK Pre-Workout
Transparent LabsBULK Pre-Workout
Informed Choice
200 mgPowder8.5
Pulse Pre-Workout
LegionPulse Pre-Workout
Third-party testedcGMP facility
350 mgPowder8.3
L-Theanine 200 mg with Suntheanine
Sports ResearchL-Theanine 200 mg with Suntheanine
Third-party testedcGMP facility
200 mgL-theanine (Suntheanine)Softgel8.0
Loaded Pre
RYSELoaded Pre		Not disclosedPowder7.9
Sleep Gummies (Blackberry Zen)
OLLYSleep Gummies (Blackberry Zen)
NSF Contents Certified
50 mgGummy7.7
Pre-Workout
Alani NuPre-Workout		200 mgPowder7.5
Energy & Focus Gum
NeuroGumEnergy & Focus Gum		60 mg per pieceChewable7.2
Dream Sleep Powder
BeamDream Sleep Powder
Third-party testedcGMP facility
300 mgPowder6.7
Magnesi-Om
Moon JuiceMagnesi-Om
Third-party tested
112 mgPowder6.5
Coffee+ Mushroom Coffee (Mild Roast)
Everyday DoseCoffee+ Mushroom Coffee (Mild Roast)		150 mgPowder6.0
Alpha BRAIN
OnnitAlpha BRAIN
Third-party tested
650 mg (blend)Onnit Flow Blend (L-tyrosine, L-theanine, oat straw extract, phosphatidylserine)Capsule5.6
Original Mental Performance Shot
Magic MindOriginal Mental Performance Shot
Third-party tested
Not disclosedReady to drink5.4
Hardcore
HydroxycutHardcore		Not disclosedL-theanine, cayenne pepper, L-tyrosine and other amino acidsCapsule4.6

Amounts are per serving as printed on each label. “Not disclosed” usually means the ingredient sits inside a proprietary blend.

Questions people ask

How much l-theanine do studies use?
Clinical studies commonly use 100–400 mg a day; 200 mg is typical.
Which l-theanine supplement scores highest?
In our reviews, Transparent Labs BULK Pre-Workout scores highest at 8.5/10, followed by Legion Pulse Pre-Workout (8.3) and Sports Research L-Theanine 200 mg with Suntheanine (8.0). Scores weigh efficacy, quality, value, experience and transparency — not just the dose.
How much l-theanine is in these products?
It varies by product and serving size — for example Transparent Labs BULK Pre-Workout (200 mg), Legion Pulse Pre-Workout (350 mg), Sports Research L-Theanine 200 mg with Suntheanine (200 mg). The table above lists the amount per serving for every product we've reviewed.

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